parallel dump fails to dump large tables

Hi,
I am having problem using parallel pg_dump feature in postgres release 9.4. The size of the table is large(54GB). The dump fails with the error: "pg_dump: [parallel archiver] a worker process died unexpectedly". After this error the pg_dump aborts. The error log file gets the following message:

2015-02-09 15:22:04 PST [8636]: [2-1] user=pdroot,db=iii,appname=pg_dump STATEMENT:  COPY iiirecord.varfield (id, field_type_tag, marc_tag, marc_ind1, marc_ind2, field_content, field_group_id, occ_num, record_id) TO stdout;
2015-02-09 15:22:04 PST [8636]: [3-1] user=pdroot,db=iii,appname=pg_dump FATAL:  connection to client lost
2015-02-09 15:22:04 PST [8636]: [4-1] user=pdroot,db=iii,appname=pg_dump STATEMENT:  COPY iiirecord.varfield (id, field_type_tag, marc_tag, marc_ind1, marc_ind2, field_content, field_group_id, occ_num, record_id) TO stdout;

Is there any config parameter that I need to set to use parallel dump for large tables.

thanks
shasingh